You can’t on the stellar fork yet. There are two kind, one(kin2) is the utility token and is the stellar fork. Kin1 is ether based and is erc20 and is what is traded.
They are working on atomic swap which should be ready in a few months.
Erc20 transactions per sec is whatever Ethereum block can handle, the stellar fork is at about 120 tps at the moment. Should get the project through early next year, but they will have to continue to itterate that to get more through put as current apps being onboarded represent many million active monthly users. As larger apps adopt they will need more to to support.
As far as I know.
If you are on Android you can download the stand alone kin app, Kinit, beta to play around with it.